Backspacing mechanism for telegraph printers



March 1, 1949. H. ANGEL 2,462,833

BACK SPACING MECHANISM FOR TELEGRAPH PRINTERS Filed Aug. a, 1946 0INVENTOR H. ANG E L BY I ATTORNEY Patented Mar. 1, 1949 BACKSPACINGMECHANISM FOR TELEGRAPH PRINTERS Herbert Angel, Brooklyn, N. Y.,assignor to The Western Union Telegraph Company, New York, N. Y., acorporation of New York Application August .6, 1946, Serial No. 688,751

7 Claims.

This invention relates primarily to telegraph mechanisms and, moreparticularly, to mechanisms whereby the movable element of a pageprinting telegraph machine such as the web holding platen carriage orthe printing unit may be back-spaced or moved in a direction opposite tothe letter spacing direction one or more character spaces.

It is often desirable in telegraphic communications to be able tocontrol a remote recording instrument so that either the platen carriageor the printing unit, whichever is movable, may be back-spaced or movedin a carriage return direction a part of a line or to some positionother than the initial starting position whereby for example a part of aline may be blanked out. Accordingly, it is one of the objects of theinvention to provide a back-spacing mechanism for a telegraph pageprinter whereby the carriage thereof may be back-spaced or moved in adirection opposite to a letter-spacing direction to any point in itspath of travel. In this connection another object of the inventionresides in the provision of means whereby the movable carriage of atelegraph page printer may be backspaced one character space at a time.

Another object of the invention resides in a provision of means ofaccomplishing the above operations wherein the receipt of a conditioningcode group conditions the receiving printer so that the receipt of codegroup which normally performs another printer function is effective toback-space the printing unit a predetermined distance for each suchreceived latter code group.

In connection with the above, -a more specific object of the inventionresides in the provision of means whereby the receipt of a carriagereturn code group, normally effective to return the carriage to aninitial position, effects movement of the carriage in a back-spacing orcarriage return direction a predetermined distance when such carriagereturn code groups are preceded by a conditioning code group.

The above and further features and objects of the invention will be moreapparent in the following detailed description wherein reference is madeto the accompanying drawings in the latter of which Fig. 1 is aperspective view of certain parts'of a page printer with the elementscomprising the 2 present invention associated. and cooperatingtherewith; and

Fig. 2 is a plan View of some of the elements of Fig. 1.

The invention as shown in the drawings and hereinafter describedas beingapplied to the telegraph page printer of the type disclosed in US.Patent No. 1,904,164, to S. Morton, granted August 18, 1933, and thesaid patent is made in a part of the present application as if includedherein. While the invention is shown applied to this particular printerit will be obvious that the principles thereof may equally well beapplied to various other printers.

The said Morton et a1. patent has a movable carriage consisting of atyping unit or type basket which moves back and forth relative to astationary recording web. In the drawings only the rack II of themovable typing unit or carriage is shown and the rack with its elementsmoves to the left as shown in the drawings one space at a time inconjunction with normal recording and Word spacing operations. Duringsuch movement of the typing unit a spring in the drum I2 is tensionedwhich is effective in response to a carriage return code group to returnthe typing unit to an initial position for the beginning of a new lineof print.

The advancement of the typing unit, wherein the rack H moves to theleft, is accomplished by rotating a gear 13 through mechanism describedand shown in the said Morton et a1. patent. The gear I3 is rotatablewith the movable upper part Id of a toothed clutch 20. The clutch alsohas a lower part l5 secured to the shaft I6 for rotation therewith. Thegear I 3 is freely mounted on the shaft [6 and the upper part [4 of theclutch is movable axially on the shaft to disengage the teeth thereoffrom those of the lower part l5. Adjacent the upper end of the shaft I6is a pinion ll engaging the teeth of the rack ll whereby rotation of theshaft and pinion effects advancement of the typing unit. The carriagreturn code group effects separation of the upper and lower parts I4 andI5, respectively, of the toothed clutch 20 whereupon the lower part I 5together with the shaft I6 and pinion I1 are free to rotate in a reversedirection through the action of the spring drum l2 tending to move therack I I toward the right.

The selecting mechanism of the printer in cludes a plurality of vanesit? which are tilted into various combinations in accordance withreceived code groups and the functions of the printer are controlled bya plurality of notched function control levers operatively associatedwith the-vanes [3. When the vanes E8 are set in certain combinations,one or more of the function levers is permitted to pivot to a selectedposition and thereby control the associated function mechanism. Such afunction lever is is employed in the present invention to condition theprinter for back-spacing movement of the printing unit or carriage. Thefunction lever I9 is pivoted on a rod 2| and has an attached spring 22norm-ally urging the same toward the vanes i8. When the vanes are set ina predetermined combination the said function lever i9 is permitted topivot in a counterclockwise direction with the edges of the vanesentering notches in the lever IS. The selector lever it has attachedthereto by a lost motion slot 23 a rod 24 and selective operation of thelever I9 moves the rod 24 toward the left to a' selected position. Therod 24 is guided adjacent its forward end in a guide post 26 and hasadjacent this end upwardly extending arms 27 and 28. Also fixed to therod 24 is a depending member 29 which has extending hor'ifintally fromthe lower end thereof a sleeve 3!. The sleeve 3! is slidable on a rod 32anchored in the guide post 26 and a spring 33 attached to the dependingmember and anchored in the post 26 tends to slide the rod 24 with itsattached elements to the right. However the spring 22 attached to thefunction lever I9 is capable of exerting a greater pull on the rod 24than the spring 33.

When the function lever I9 pivots in a clockwise direction and moves therod 24 to the left,

such movement of the rod places the horizontal upper end of the arm 28beneath a latching lever 34. The latching lever 34- is pivoted on ashoulder screw 36 and with the end of the arm28 beneath this lever it isprevented from operating to latch the carriage return lever 37! in anoperated position. When movement of the latch lever 34 is not blocked bythe arm 28 it is operative to engage a shoulder 38 on the carriagereturn lever 3i and latch the same in an operated position. Suchoperation of the latch lever 34 occurs during a normal carriage returnfunction of the printer. Near the end of a normal carriage returnfunction, the carriage engages and pivots the lever 39 in a clockwisedirection about the pivot 4!, as viewed from above, so that the lever 39engages the depending arm 42 of the latch lever 34 and moves the sameout of engagement with the notch 38 of the lever 31 whereupon the lever31 returns to its normal position.

,Movement of the rod 24 to the left or toward the vanes l8, also movesthe sleeve 3! out from beneath the end of an arm 43 secured to a pivotrod 44 whereupon the spring 46 pivots thearm down onto the rod 32. Therod 24 with its attached elements is thereby locked in its operativeposition but because of the lost motion slot 23 in the end of the rod24, the lever 19 can return to its normal position while the rod islocked in this selected position. The above movement of the arm 43 rocksthe rod 44 in a clockwise direction so that the upper end of an arm 4'!thereon moves away from the edge of a pawl 48 pivoted on a shoulderscrew 49. This movement of the rod 44 also moves a third arm thereoninto a position to be operated by a cam 52. v 1

The pawl 48 has extending therefrom a pin 53 to which is attached aspring 54 tending to pivot the pawl in a clockwise direction as viewedin Fig. 2. Such pivoting of the pawl, however, is normally prevented byan arm 56 engaging the surface 5'! on the pawl. Selective operation ofthe rod 24 through its arm 21 causes the shaft 58 upon which the arm 56is mounted to pivot against the action of a spring 59 and thereby movesthe arm 33 out of operative relation with the surface 51 of the pawl 48.

The pawl 48 is thereupon free to pivot in a clockwise direction asviewed in Fig. 2 and moves the hooked end 6! thereof into engagementwith a ratchet wheel 62. The ratchet wheel 62 is secured for rotationtherewith to the shaft l6 and with the pawl 48 engaging a tooth or theratchet wheel 62, rotation of the shaft in a clockwise direction isprevented.

In the preferred embodiment of the invention the carriage return codegroup is employed to back-space the carriage a predetermined distancewhen such code groups follow the receipt of the conditioning code group.When a carriage return code group is not preceded by a back-spacingconditioning code group, the carriageis returned in the usual mannerfrom any point in itspath of travel to its initial starting position.Through mechanisms fully described and shown in the above-mentionedMorton et al. patent the receipt of a carriage return signalcausespivotingofa lever 63 to disengage the elements I4 and I5 of thetoothed clutch 2i] whereupon the spring drum i2 is effective to performa carriage return'func tion. The lever 53 when operated by means of alink 64 and a bell crank 66 causes movement of the carriage return lever31 toward theleft. If the carriage return code group is preceded by theconditioning code group which effects selective operation of the rod 24,.the lever 31 will not be latched in its operated position by the latchlever 34 since the latch lever in the manner described, will beprevented from moViIlg to a latching position. operating elements whichcontrol the lever 31 will immediately return to their normal positionwhen such operation occurs with the rod 24' in a selected position,

The selective operation of the rod 24 as above described permits thepawl 48 to move into operative relation with the ratchet wheel 62 andthereby prevents rotation of the ratchet wheel infthe direction itrotates during a carriage return function. However, in response to acarriage return signal the pawl 48, in the manner to be, described, ismomentarily operated to permit the ratchet. wheel 62 to rotate in areverse direction one. tooth and permits back-spacing of the carriage.acorresponding distance.

The lever 31 has extending upwardly therefrom a projection 61 inoperative relation with the, free end of an arm 88 pivotally mounted. ona shoulder screw 69. The arm 68 has pivotally attached'thereto by meansof a shoulder screw I H a pawl operating member 12. As the lever 3!moves to the left in response to a carriage return code group, theprojection 61 engages the arm 68 to pivot the same in a clockwisedirection. This movement of the arm 68 causes a shoulder 73 on themember 12 to engage the pin 53 on the pawl 48 and pivot the same in a.counterclockwise direction against the action of its attached spring54. This movement of the pawl-48 with draws the hooked end 6| out ofengagement with a tooth. of the ratchet $2 whereupon the-ratchet is freeto rotate in a clockwise direction and Accordingly the carriage returnpermit back-spacing movement of the carriage. However, the hooked end 6|of the pawl 48 permits the ratchet 62 to rotate only one tooth since thepawl 48 returns to an operated position in time to engage the nexttooth. The momentary operation of the pawl 48 is accomplished bydisengaging the shoulder 13 from the pin 53 just as the pawl is movedsufficiently to disengage a tooth of the ratchet. This disengagement isefiected by pivoting the member 12 which is accomplished by the camsurface 14 thereon engaging the stationary pin 76, Thus in response to acarriage return code group following the back-spacin conditioning codegroup, the carriage return code group effects operation of the lever 31and the ratchet wheel 62 is permitted to rotate in a reverse directionone tooth or in the direction permitting back-spacing of the carriage apredetermined distance for each carriage return code group.

The back-spacing movement of the carriage will continue for eachreceived carriage return code group following the conditioning signal oruntil the receipt of an unconditioning code group. In the preferredembodiment of the invention an unconditioning code group consists of anycode group which effects a printing operation and in such operations thecam 52, through mechanisms fully described in the above-mentionedpatent, makes one revolution. Such operation of the cam 52 permits thelobe thereon to engage the end of the arm 5! and effects rocking of therod 44 in a counterclockwise direction. This rocking of the rod 44 movesthe end of the arm 43 out of blocking engagement with the end of thesleeve 3| whereupon the sleeve 3| together with the rod 24 and itsattached arms are permitted under the influence of spring 33 to movetoward the right back into a normal position. Such rocking of the rod 44also through the arm 41 engaging the pawl 48 moves the pawl back into anunoperated position whereupon the arm 56 on rod 58 latches the same inthis unoperated position. Thus the back-spacing mechanism is returned toits normal unoperated position and the printer is conditioned to operatein accordance with received code groups in the usual' manner.

While this invention has been described in a preferred embodimentthereof, it will be obvious that various modifications thereof may bemade without departing from the spirit or essential attributes thereofand it is desired, therefore, that only'such limitations be placedthereon as are specifically set forth in the appended claims.

What is claimed is:

1. In a printing telegraph machine, a carriage normally movablestep-by-step in an advancing letter-spacing direction in conjunctionwith printing and word spacing operations of said machine, means forcontinuously moving said carriage in a reverse direction to an initialposition in response to a first predetermined code group and meansresponsive to a second predetermined code group to condition saidmachine to efiect movement of said carriage in said reverse direction apredetermined distance in response to following code groups of saidfirst predetermined character.

2. In a printing telegraph machine, a carriage normally movablestep-by-step in an advancing letter-spacing direction in conjunctionwith printing and word spacing operations of said machine, means forcontinuously moving said carriage in a reverse direction to an initialposition 6. in response to a first predetermined code group, meansresponsive to a second predetermined code group to condition saidmachine to effect movement of said carriage in said reverse direction apredetermined distance in response to following code groups of saidfirst predetermined character, and means responsive to any one of aplurality of other code groups to restore said machine to normal wherebysaid carriage movement is effected in said normal manner.

3. In a printing telegraph machine, a carriage normally movablestep-by-step in an advancing letter-spacing direction in conjunctionwith printing and word spacing operations of said machine andcontinuously in a reverse direction to an initial position in responseto a first predetermined code group, a normally inoperativecarriageback-spacing mechanism, means responsive to a secondpredetermined code group to condition said back-spacing mechanism foroperation and means responsive thereafter to said first predeterminedcode group to operate said backspacing mechanism to back-space saidcarriage a predetermined distance in conjunction with the receipt ofeach of said first predetermined code groups.

4. In a printing telegraph machine, a carriage normally movablestep-by-step in an advancing letter-spacing direction in response toprinting and word spacing code groups and continuously in a reversedirection from any point in its path of travel to an initial position inresponse to a carriage return code group, a normally unoperativeauxiliary mechanism adapted to move said carriage in said reversedirection a predetermined distance on each operation, means operative onthe receipt of a second predetermined code group for operativelyconditioning said mechanism and means operative thereafter in responseto said carriage return code groups to operate said mechanism.

5. In a printing telegraph machine, a carriage normally movablestep-by-step in an advancing letter-spacing direction in response toprinting and word spacing code groups and continuously from any point inits path of travel in a reverse direction to an initial position inresponse to a first predetermined code group, a normally unoperativeback-spacing mechanism for moving said carriage in said reversedirection a predetermined distance on each operation thereof, signalcontrolled means for conditioning said backspacing mechanism foroperation and other signal controlled means effective after theoperative conditioning of said mechanism to operate the same toback-space said carriage.

6. In a printing telegraph machine, a carriage normally movablestep-by-step in an advancing letter-spacing direction in conjunctionwith printing and word spacing operations of said machine andcontinuously in a reverse direction to an initial position in responseto a first predetermined code group, a normally unoperative backspacingmechanism for moving said carriage in said reverse direction apredetermined distance on each operation thereof, signal controlledmeans for conditioning said back-spacing mechanism for operation, other.signal controlled means effective after the operative conditioning ofsaid mechanism to operate the same to backspace said carriage, and stillother signal controlled means operative to restore said backspacingmechanism to its normal condition.

'7. In a telegraph recorder, a carriage movable amazes;

7, in an advancing .letter-spacingsdirection against the action of a,resilient, membertending to retumsaid carriage to an initial position, atoothed ratchet-wheel rotated during, movement of said carriage, aratchet pawl normally out of operative relation with said ratchet wheel,means responsive to a first code group to move said pawl into engagementwith said ratchet wheel and thereby prevent rotation thereof andmovementof said carriage in apreverse direction and other signal responsivemeans for operating said pawl to release said ratchet wheel for apredetermined part of a revolution whereby said resilient mem-v ber v isefiectivento move .v said carriage a corne spondingdistance in la'carriage return direction;

- HERBERT ANGELL REFERENCES CITED file of this patent:

UNITED STATESPATENTS 7 Number. Name Date 7 1,171,379.. Wright Feb. 8;1916' 1,370,669.? Potts Mar. 8, 1921 Martinet a1. June 3,- 1941-

